Guitarists must have control over their amplifier. They must be able to interact with it through their electric guitar. It's my own belief that this is what makes a tube amplifier the only way to go. Why? A tube amplifier reacts much stronger to any little change in the signal it receives from the guitar. While it's harder to learn to control because of its sensitivity it's this very sensitivity that allows for the wide palette of sound the Dino guitarist seeks to create. Also, a tube amplifier can slip beautifully into and out of a gain voicing. Pick a note through a solid state amp at high gain levels and allow it to decay. It starts out high gain, starts to lose volume, and then drops off a cliff into clean territory as it tails off. Pick a note through a tube amp at high gain levels and allow it to decay. It starts out high gain, starts to lose volume, and then slowly and smoothly while retaining its gain voicing tails away in a beautifully vocal manner. Pick a string on your guitar multiple times while running into a solid state amp. Pick it hard. Pick it soft. Pick it with your finger, your thumb. Mix in up strokes. What do you hear from the amp.? Changes of volume and drive. Now do the same thing while running into a tube amp. What do you hear from this amp? Changes in volume, drive, texture, attack, gain voicing, different frequency bands becoming more or less prominent, changing overtones, changes in the way a note blooms.
Most guitar players at the present time, mainy because of price considerations, start their life as a player using a solid state amp. For most it's a modeling amp. There's no denying that instant gratification, for the inexperienced player lacking exposure to quality equipment, is available in a modeling amp. It can produce gain, in a hissy / nasally manner, provide access to multiple effects, that a beginner or anyone lacking in experience can use to explore the myriad types available. To learn to match the name of an effect to an approximate representation, and it won't break the bank. Some won't even break a piggy bank. For a child starting out or even a young adult it's a good way to amplify the guitar for the period of time needed to see if the player has the talent and desire to really stick with it. But, once that desire and talent has been established, an amp of this type's continued use will only be a detriment to the players tonal aspirations.
I would recommend to all teachers and parents that they move the student player from solid state to tube as soon as their talent and desire to play has been established. Far too many players get used to the instant gratification and ease of use of a solid state amp and then dislike the learning curve involved with switching to a tube amp at a later date. The electric guitar and the tube amplifier should be approached and learned in unison. One interplays with the other. They're a team. A dude who sticks with solid state, no matter what their skill level is on the electric guitar, will never achieve a tone to match their technique. Tone is a terrible thing to waste.