I agree with everything that you said. Much was expected from Chelsea yesterday, but they gave little. However, Crystal Palace is a pain on the ass for big clubs in EPL. They have defeated Manchester City and Liverpool in the finals. This shows that Chelsea tried their best to draw the match. I just observed that any team that defeat Liverpool, Arsenal or Manchester City finds it difficult to defeat Chelsea.
Crystal Palace at the good trend after success defeating any top big four teams since FA Cup final defeating Manchester City and last weeks success getting victory over Liverpool at FA Community Shield Final match. Chelsea's fans expected easily for winning the match against Crystal Palace after becoming the winner at FIFA Club World Cup by defeating PSG but not easily against Crystal Palace. In other side Chelsea get advantage after Crystal Palace goal disallow and seems not really bad getting one point at first premier league match.
Next match, Chelsea have opportunity get the victory against the loser team West Ham United defeating at the first match from promotion team Sunderland, its great chance how last match West Ham conceded three goals and should be easily for Chelsea getting three points. Regarding premier league matches schedule, Chelsea have advantage by facing mediocre teams for several matches later and should get three points before facing the big four team.