Longevity? Murph played 18 seasons.
Two good seasons? Murph had 7 good seasons, 7 border line great seasons.
In 1980 Murphy's core numbers were 33-89-.281
From 1982-1987 Murphy played every game *EVERY GAME*
In those six consecutive seasons he *averaged* 36 homers, 105 RBI's, 110 runs scored, 18 stolen bases, .289 BA, .382 OBA, a ridiculuous .913 OPS, an eye popping OPS+ of 145.
In those six years I speak of, he won 4 Silver Sluggers, 5 Gold Gloves, and was one of the greatest defensive outfielders of my generation, not that it means much, but he played the game right, never disgraced the game, and never did anything artificial, unless you count pounding the free weights in the gym artificial.
Your longevity argumetnt is invalid.
Your 2 good seasons argument is invalid.
You want to knock Murph, you could say he struck out too much, you could say his .265 overall batting average in his 18 years is not Hall worthy, but he hit almost 400 homers (398) and drove in almost 1300 runs.