I don't mind Season 1 that much, but yeah, parts of it were a bit bland thinking of it now (just thinking of episodes like Suited for Success and Look Before You Sleep) and as for Season 4, I've just about completed watching it and I can agree with anyone who said that it had its share of boring/sloppy/stupid moments and all the "OMG!!!!! TWILIGHT SPARKLE IS A PRINCESS!!!!!!!" moments were just grating for me to hear. But at least episodes like Maud Pie and Daring Don't kept me entertained. I do think Season 4 was alright for what it is.
If anything, I think it is possibly just that feeling we call nostalgia playing tricks on some of us from the community. Hey, it happens! I've felt nostalgia before!