Crito is anxious about the education of his children, one of whom is
growing up. The description of Dionysodorus and Euthydemus suggests to him
the reflection that the professors of education are strange beings.
Socrates consoles him with the remark that the good in all professions are
few, and recommends that 'he and his house' should continue to serve
philosophy, and not mind about its professors.

...

There is a stage in the history of philosophy in which the old is dying
out, and the new has not yet come into full life. Great philosophies like
the Eleatic or Heraclitean, which have enlarged the boundaries of the human
mind, begin to pass away in words. They subsist only as forms which have
rooted themselves in language--as troublesome elements of thought which
cannot be either used or explained away. The same absoluteness which was
once attributed to abstractions is now attached to the words which are the
signs of them. The philosophy which in the first and second generation was
a great and inspiring effort of reflection, in the third becomes
sophistical, verbal, eristic.

It is this stage of philosophy which Plato satirises in the Euthydemus.
The fallacies which are noted by him appear trifling to us now, but they
were not trifling in the age before logic, in the decline of the earlier
Greek philosophies, at a time when language was first beginning to perplex
human thought. Besides he is caricaturing them; they probably received
more subtle forms at the hands of those who seriously maintained them.
They are patent to us in Plato, and we are inclined to wonder how any one
could ever have been deceived by them; but we must remember also that there
was a time when the human mind was only with great difficulty disentangled
from such fallacies.