my last band use to do that once in awhile, never thought it as unprofessional, I just thought it was normal, I didn't have anything "impressive" to noodle inbetween songs so I usually always stayed quiet and just wanted to get to the next song, then our band got lazy, well I guess our singer in general got lazy and every show we played for a long time he never bothered doing a set list anymore, just winged it, which got annoying because it probably looked ******** with all of us looking at each other on stage going "what do you wanna play?" "I dunno, what do you wanna play?"
then we got a lead guitarists that could shread like no tomorrow, great guy, loves his guitar, almost to much, THATS when noodling got annoying is when it got frequent, and he's kind of a drunk noodler (meaning he noodled more the more drunk he got) between almost every song he would rip out a shread scale, and if he's really drunk, he would rip out old school metal songs like pantera which would annoy the HELL out of me because 1) no one in the band knows it completely, 2) as stated above, the crowd hers it, gets excited, sees we don't/can't pull it off, and lose respect for us,
so now that I know that people view it as unprofessional I'm really glad I left that band cause all in all it was a waste of my time, though the 3 years I played I learned alot about gigging and got ALOT better at bass playing, still got a long way to go, but atleast I'm mildly decent, and surprisingly have alot of respect from alot of people who have seen me live, though they flatter me with their "oh your so amazing" when really, I'm average IF that. woops, started to ramble