[loa_in_]

It serves a purpose if it's to cater to a user who appreciates that.

You could argue that software displaying "Good Morning, <name>!" every first run of the day serves no technical purpose, and judging by the tone of your comment, it makes that software inferior and the developer who decided to include this feature - to be of ill mind and immature.

I like to say that seriousness, like fear, will make us do and say stupid things if we let it take over us.

[RaleyField]

For one thing you are using exclamation point. However your example isn't really pushing personality onto users, some polite playfulness can be welcome. An example of what I had in mind that isn't in itself of poor taste but would still be unwelcome at least to me would be if somebody was pushing their metal subculture into their spreadsheet software for no apparent reason.