No, not really. It's pretty popular. 8 and especially 2 are the ones people think are weaker (and Shadow Dragon to a smaller extent). And it's not like Fire Emblem plots are often anything to write home about.
Shadow Dragon is much less popular than 8, don't kid yourself. Also, 1-3 (the originals) are all unpopular as well. (Though, in general, for Japanese-only FEs except 4, 6, and 3DS, I'd suggest the number of English-speakers who have played it is perhaps too small a sample size to talk about the games' popularity.)
All FE plots suck (4-5 may suck less, don't really care), I actually thought FE10's was above average for the series but I'm not interested in discussing it. FE10 has clearly better gameplay than most of the series... in general, aside from the occasional step back, the gameplay in the main series has only gotten better! FE10, in particular, made you effectively use a large number of characters (instead of the usual 10-12, then ignore everyone else) in efficient play, had a skill system in which you actually had to make decisions ("do I move this skill to another PC and incur a CP cost, or not?" etc.), and in general had FE9's gameplay with a whole bunch of polish improvements: being able to see things like the WExp gauge, AS actually shown in the status screen, S/SS-rank weapons actually being in the game. The last bosses with their tricks and multitarget attacks were also way more epic than anything in any previous Fire Emblem (lol at FE6-9's final bosses) although still easy enough with a powerful team obviously.
--
The RPG Duelling League: www.rpgdl.com
An unparalleled source for RPG information and discussion