While one cannot totally rate a player based on the ratings, I does offer some insight into a players career and stats.
Wasim Akram for example is universally lauded, he never cracked the 900 ratings barrier because of his disproportionately high number of lower order wickets taken. It doesn't make him a bad bowler, just makes us take a second look or ask more questions.
Additioally its not so much your peak total thats more important, but the percentage of tour career spent over 900. That is the most telling as it speaks to consistent brilliance and not just one good year or season.