Across theistic religions, worshipping God is considered a means to a favorable end. And God himself suggests this, according to texts of those religions. Further, worshippers of God are excused from punishments for their grave mistakes, just because they have been devout. All of this is narcissism or egoistic behavior, say the naysayers (here).
Ofcourse there are counter-arguments across theistic schools of thought:
God is altruistic beyond measure.
God is self-sufficient. He does not need any endorsements or validations for his greatness.
From a Vedantic viewpoint -
Brahman is AptakAma - one whose wishes become real instantly. He has nothing to gain from these praises or worship or devotion.
He is Infinite Bliss himself. No amount of devotion (or anything) can add anything to it.
The silliness of the idea that God needs our worship, stotras as a validation, is mocked well, though indirectly, in Shri Jagannatha Dasa's Harikathāmṛtasāra. He likens our stotras to a toddler's initial words (bālakana kalabhāṣe) which mean nothing but are still valued by the mother. Similarly, we may consider our stotras profound but they do not capture God's majesty even infinitesimally. How can that be validation or egoistic behavior then?
Shrimad Anandatirtha Bhagavatpadacharya hints at some more arguments, in his Bhagavata-Tatparya.
Context:
Bhagavata 7.1.27 seems to accept hatred (towards Bhagavan) as a means to reach Lord.
The 28th verses is explicit -
यथा वैरानुबन्धेन मर्त्यस्तन्मयतामियात् । न तथा भक्तियोगेन इति मे निश्चिता मतिः ॥
The apparent meaning of this verse is that Narada Muni considers Vaira (enemity) towards Bhagavaan to be most effective means, better than even bhaktiyoga, to become wholly absorbed in (thinking about) Him.
Ofcourse Acharya corrects the aforegiven absurd interpretation which is contrary to all other injunctions, which praise Bhakti as the most important means and which condemn Dvesha as a means to get to Andhatamas. He points out that the 27th verse is not an injunction to develop hatred but a description of different people's sAdhana. He gives references from Gita and Bhagavata itself to show that Dvesha leads to Hell and therefore to be avoided.
Acharya uses examples of Śiśupāla etc., in whose body were present two souls, an intrinsic devotee overpowered by an intrinsic hater. His interpretation is very elaborate and deserves separate attention altogether.
However, he mentions few points, which are of interest to us in the current topic.
He says:
यस्मादेवं कोऽप्युपद्रवो नास्ति भगवतस्तस्मादेव द्वेषादिनाऽपि मनो योक्तुं शक्यते तत्प्रेरणया । तादृशानां तदेव चिन्तयति च ।
अन्यथाऽऽत्मनो दुःखकारणं द्वेषादिकं कथं सर्वनियामको हरिरुत्पादयेत् ॥ (1)
Since there is no perturbance to Bhagavan on the account of hatred, he makes these intrinsic devotees like Jaya Vijaya even develop hatred (due to their own karma), fear etc. and later remove that hatred. For those who have innate hatred (like Jarasandha) for Bhagavan, he does intentionally manifest that dvesha. Else, how can Shri Hari, who is indeed the controller of all (beings and their feelings), develop hatred (towards Himself) in such people?
That is, Bhagavan is not impacted, not in the least bit, by others' ill-feelings / hatred towards Him. That is why He allows dveSha to develop even in innate devotees (on the account of their karma and later remove that hatred on the account of their svabhaava).
Acharya mentions a couple of interesting points in the commentary on the next verse:
Only on the account of the fact that Bhagavan is not perturbed by others' hatred for him, he lets these people like Śiśupāla develop hatred (for) Him. Else, he would have created more devotees than haters (तत्कथं अन्यथा भक्तानेव बहून् हरिः कुर्यादिति भावः). On the other hand, the shruti ततः कनीयसा एव देवा ज्यायसा आसुराः (Brihadaranyaka Upanishat) tells us that there are more asuras (haters) than devotees (deva) of Bhagavan. (2)
Bhagavan is not perturbed even when there is loss of devotion (which happens when devotees die or suffer from diseases or get into asurAvesha).(3)
Vaira (enemity) towards Bhagavaan is persistent, forceful and without any mixture. On the other hand, devotion (during samsAra) is generally mixed with fear or anger towards Bhagavan. Only Chaturmukha Brahma is the exception!
मागधाद्या यथा नित्यं द्वेषादाग्रहिणो हरौ । न तथा आग्रहिणो भक्ता विना ब्रह्माणमव्ययम् - इति हरिवंशेषु ॥
The Harivamsha states that Jarasandha etc. are always obsessed with Hari on the account of their hatred. The devotees are not like that (neither are they obsessed nor is it persistent), except in Chaturmukha Brahma.(4)
To summarise the 4 relevant points: Our Bhagavan's creation comprises more haters than devotees. He lets hatred develop even in some devotees like Śiśupāla (depending on their karma). Even the said devotion has a mixture of fear and indignation, except in Rujus. Bhagavan suffers no dimunition even when devotion reduces.
All of the above show that Bhagavan is not narcissistic at all. Had He been so, He would have changed everybody to a devotee. After all He is sarvaniyAmaka. And He would have chosen to have more devotees than innate Haters.
He is not a masochist (inflicts pain to oneself) either. In addition to above reasons, it is also true that He does not reward the haters!
We can observe that the above reasons can be provided only in our school of Vedanta - which accepts that some souls have innate hatred yet the Lord behaves very justly with them, like he does with devotees. This interpretation of Shrimad Anandatirtha Bhagavatpadacharya provides us a better understanding of Bhagavan's own statement -
समोऽहं सर्वभूतेषु न मे द्वेष्योऽस्ति न प्रियः । ये भजन्ति तु मां भक्त्या मयि ते तेषु चाप्यहम् ॥ (9.29).
श्री मध्वेशकृष्णार्पणमस्तु
p.s. the commentaries on the referred Bhagavata tatparya verses are quite varied and make for a very interesting read.